Problem: $z=-400i-44.5$ What is the real part of $z$ ?
Explanation: Background Complex numbers are numbers of the form $z={a}+{b}i$, where $i$ is the imaginary unit and ${a}$ and ${b}$ are real numbers. [What is the imaginary unit?] The real part of $z$ is denoted by $\text{Re}(z)={a}$. The imaginary part of $z$ is denoted by $\text{Im}(z)={b}.$ Finding the Real and Imaginary Parts of $z$ In this case, $z={-400}i-{44.5}$ is of the form ${b}i+{a}$, where ${a}={-44.5}$ and ${b}={-400}$. Therefore: $\text{Re}(z)={a}={-44.5}$. $\text{Im}(z)={b}={-400}$. Summary The real part of $z$ is ${-44.5}$. The imaginary part of $z$ is ${-400}$.